tonight the ntsb says it's already begun interviewing the four pilots on board. the two flying the jet and the relief crew. dan simon takes a look. >> investigators believe as asiana flight 214 was on final approach to san francisco international airport, its air speed was far too slow. >> about three seconds prior to impact, the flight data recorder recorded its lowest speed of 103 knots. at this time, the engines were at about 50% power and engine power was increasing. >> that meant that the pilot at the controls was frantically trying to power up, because he realized he was coming in too low. that pilot while experienced flying 747s according to the airline, had only limited experience flying a boeing 777. just 43 hours. he had never landed that type of plane in san francisco. in this exclusive video obtained by cnn, you can see the plane start to descend, it then appears to strike the seawall, loses control and crashes. >> he was also flying with a check captain or a training captain. there were two other crew members, another captain and first officer who we